I'm working on getting back to this issue. I still have some hunting when I start that smooths out in about a minute or two. I'm still getting a dwell reading of around 54 with little fluctuation. I'm about to borrow someone else's lambda ECU to see it the reading changes.
Is the wire from the CO2 to the lambda ECU suppose to show a voltage? I put a multimeter on the wire where it connects to the wire going directly to the ECU. I didn't read any voltage. I will say that I may not have set the multimeter to the right setting (200ma) or perhaps it was not grounded properly. I also found a small cut in the wire. It looks like a few strands may have been cut. The CO2 sensor is fairly new, replaced last year.